Maricopa County tap water
6 of 41 water systems serving Maricopa County with full PFAS testing averaged above a 2024 federal PFAS level at one or more sampling points.
- 100 community water systems list this county as served; 41 serve 3,300+ people with full PFAS testing.
- 24 had a health-based violation since 2021-10-26.
Largest systems serving this county
| System | Source | People served (whole system) | PFAS above a 2024 level? | Violations since 2021-10-26 |
|---|---|---|---|---|
| Phoenix City of | Surface water | 1,695,000 | No | 0 |
| Mesa City of | Surface water | 466,000 | No | 0 |
| Gilbert, Town of | Surface water | 247,600 | Yes | 0 |
| Chandler City of | Surface water | 247,328 | No | 0 |
| Scottsdale City of | Surface water | 241,361 | No | 0 |
| Glendale City of | Surface water | 234,766 | No | 0 |
| Peoria City of | Surface water | 187,676 | No | 0 |
| Tempe City of | Surface water | 165,000 | Yes | 0 |
| Epcor - Agua Fria | Surface water | 128,040 | No | 2 |
| Avondale City of | Purchased surface water | 96,130 | Yes | 0 |
| Queen Creek Town of | Groundwater | 95,502 | No | 0 |
| Liberty Water Lpsco | Groundwater | 57,070 | Yes | 1 |
Which one is yours? A county usually has several utilities. Your bill or your utility's annual water-quality report names yours. Population is for the whole system, which can cross county lines.
Not medical or legal advice. UCMR 5 results are screening data, not compliance determinations.
Sources and freshness
Public-water-system facts, violations and lead/copper results: EPA ECHO SDWA download (SDWIS snapshot 2026-10-13). PFAS and lithium results: EPA UCMR 5 final data (sampling 2023–2025). Both are U.S. government works, downloaded 2026-10-26. Numbers are computed by the published method; the same fields are in the open data files.